Printer



W. A. KOEHN July 7, 1964 PRINTER -mUHrHIH IN VEN TOR. WML/,4M A Kf//A/ Armen/5r United States Patent O 3,139,81s PRINTER William A. Koehn, Pasadena, Calif., assgnor to Clary Corporation, San Gabriel, Calif., a corporation of California Filed Feb. 23, 1961, Ser. No. 91,179 3 Claims. (Cl. 1111-93) This invention relates to high speed printers, of the type basically disclosed, for example, in the patents to Goldberg et al., 2,799,222, issued on July 16, 1957 and Witt et al., 2,915,968, issued on December 8, 1959.

In such printers, wherein a type carrying member having one or more endless columns of type characters is moved past a row of printing impression devices or hammers, the time generally required to print a line of type is the time which elapses from the instant that a predetermined point on the type carrying member passes such row until a second predetermined point passes that row. In the case of a iixed print-start system, the type carrying member moves idly past the row of impression devices until such predetermined point is reached. Then, time must be allotted for all type characters in a full set or font to pass such row of impression devices before the paper can be advanced to print the next line. Obviously, more or less wasted time is involved depending on the particular values being printed.

In order to reduce such printing time, other systems have been devolved using a random print-start arrangement wherein printing may commence at random when any type character passes the impression devices and will terminate after a number of diiferent type characters equal to the total number of characters in the full font have passed the impression devices, after which the paper is advanced to a new line position preparatory to printing a new line of print.

Although the random print-start system saves a certain amount of printing time by eliminating the wasted part of the type member movement preceding the first printing operation, still more or less time is wasted depending on the particular value being printed. Consider a case where a type drum contains a font of numerical type characters only. If a row of 1 type characters on the drum were approaching a row of impression devices, and if the value to be printed were 11111, it will be seen that the entire printing operation will occur early in the rotation of the drum and considerable time would be thereafter Wasted until the balance of the type characters in the font or, for example, the type characters 2 to 9 and "0 have idly passed the row of impression devices before the paper could be advanced to commence printing a new line.

It therefore becomes a principal object of the present invention to reduce wasted time in a printer of the above type.

Another object is to increase the printing speed of a printer of the above type.

Another object is to simplify the circuitry for controlling a printer of the above type.

The manner in which the above and other objects of the invention are accomplished will be readily understood on reference to the following specication when read in conjunction with the accompanying drawings, whereinz' FIG. 1 is a schematic diagram of the wiring circuit for controlling a high speed printer and embodying the present invention.

FIG. 2 is a diagrammatic side view of one form of printer which may be incorporated in the present invention.

Referring to the drawings, the printer disclosed therein comprises a continuously rotatable type drum 11 having 3,139,818 Patented July 7, 1964 a number of columns 12 of type characters spaced therearound. Aligned with each column 12 is a hammer 13 pivotally supported at 14 and normally held by a tension spring 15 out of contact with the type drum. The right-hand end of each hammer forms an armature which cooperates with an electromagnet 16, whereby energization of the magnet will rock the hammer clockwise and thus effect a printing impression from a selected type character on the drum onto a strip of paper 17. The latter is guided over rollers 18 and 19.

The paper is advanced past the hammers 13 by a feed roll 20 to which is attached a ratchet wheel 21 and cooperates with roller 19. The ratchet Wheel is engageable by a pawl 22 carried on an arm 23 pivotally supported for movement about the axis of rotation of the feed roll 20. The arm 23 forms an armature which cooperates with a solenoid 24 so that upon energization of the solenoid 24, the arm 23 will be rocked counterclockwise against the action of a tension spring 25 to advance the feed roll in a similar direction.

Describing now the electrical controls for the printer, data is received in binary coded decimal form from suitable data processing apparatus, not shown, over a number of sets of lines 26 to 30, inclusive, one for each column of type characters.

The lines of each set 26, etc., represent diiferent weighted values in the binary scale of progression. For example, the lines in each set, counting from the uppermost one, represent the decimal values 1, 2, 4, 8, respectively, and a blank or no print indication. Decimally equivalent values ranging from 0 to 9 are thus registered by relatively high potentials on one or more of such lines except the lowermost line, which represents a blank only.

The drum 12 has a circular row of contacts 31 arranged concentrically thereabout, there being one such contact for each type character space around the drum. The contacts are wiped by a brush device 32 which is connected through a line 33 to the input of a 10-state counter 34. The latter is of the binary type having four output lines 35 which register diiferent weighted values in accordance with the scale of binary progression. Such weighted values are the same as those registered by the different digital lines of the input sets 26 to 30. That is, counting down from the uppermost line, the lines 35 represent the decimal values l, 2, 4 and 8. Thus, decimal values ranging from 0 to 9, corresponding to the different type character positions around the drum, are successively registered by application of relatively high potentials on one or a combination of the output line 35.

The sets of lines 26 to 30 are connected as inputs to respective multiple input gates 36 to 40, respectively. The latter may be of any well known type such as that disclosed and claimed in the copending application of R. E. Loudon, Serial No. 172,364, filed January 15, 1962.

The set of output lines 35 of counter 34 is connected in parallel to the opposite inputs of such gates. Now, when the count registered by the counter 34 matches the amount registered by one or more of the sets of input lines 26 to 39, an output will be generated by the associated gate. The output of each gate is connected through an output line, i.e., 41, and amplifier, i.e., 42, to an associated hammer magnet indicated by the arrow 16 in FIG. 1.

It should be noted that data is received over the iive sets of data lines 26 to 30 in sequence from the data processing apparatus. That is, data is first received over one or more of the uppermost four lines in the set 26 or an indication of a non-print operation in the corresponding column is received over the lowermost line 43 of that set. Thereafter, data is similarly received over the set 27, etc. Such sequence, however, is completed while the output of the counter registers a current count, i.e., while the brush 32 remains in wiping engagement with one of the contacts 31.

In accordance with the present invention, the blank indicating lines, i.e., 43, of each of the sets 26 to 30 is connected through a line 44 to the input of an N state electronic counter 45. The latter may be of any well known type such as that disclosed in Patent No. 2,988,275, issued on June 13, 1961 to T. H. Thomason. The counter 45 is arranged to count to a predetermined value equal to the number of columns 12 of type characters and their corresponding printing impression devices. Also, each of the outputs of the gates 36 to 40 is connected through a line, i.e., 82, and a line 47 to the input of counter 45. Thus, upon receipt of a blank signal, or upon receipt of an output pulse from any of the gates 36 to 40, a count pulse will be applied to the counter 45.

Accordingly, after a line of characters is printed by the hammers 13, or after certain character spaces in such line are printed and an indication of a blank or non- -print is received regarding each of the other character spaces in such print line, the counter 45 will lill to its predetermined value and transfer a control pulse to a paper advance circuit 46 which is effective to energize the paper advance magnet 24. Also, at this time, the counter will automatically reset to enable recycling.

Obviously, two or more fonts of type characters may be spaced around the drum in each column 12 with an appropriate number of contacts 31 likewise spaced therearound. Also, the drum may be modified to accommodate any desired number of characters in a font. For example, such font may include both alphabetical as well as numerical type characters, in which case the counter 34 would be expanded to register a number of states equal to the number of type characters in such font, and the number of lines in the sets 26 to 30 and 35 Would be increased to accommodate registration of amounts corresponding to the number of such type characters.

Ir desired, the data received over lines 26 to 30 could be transmitted simultaneously, in which case suitable delay circuits (not shown) of different delay time characteristics would be connected in the lines 43 and in the lines 82 connecting the outputs of the gates, i.e., 36, to the line 47 so as to appropriately actuate the counter 45.

Although the invention is described in detail and therefore certain specic terms and languages are used herein, it is to be understood that the present disclosure is illustrative rather than restrictive and that changes and modiications rnay be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what is desired to secure by United States Letters Patent is:

1. Printing mechanism comprising the combination of a type member having a plurality of type characters,

thereon, a plurality of impression devices associated with said type member for obtaining printing impressions of selected ones of said type characters, means for advancing said type member past said impression devices, means for guiding a record medium between said type member and said impression devices, a counter, said counter being adapted to till upon reaching a count equal to the number of said impression devices, means for selectively actuating said impression devices, means for selectively presenting pulses indicating that certain of said impression devices are not to effect a printing impression, means responsive to operation of each of said last two mentioned means for actuating said counter, and means responsive to lling of said counter for advancing said record medium past said impression devices.

2. Printing mechanism comprising the combination of a type drum having a plurality of columns of type characters spaced therearound, a plurality of impression devices for obtaining printing impressions of selected ones of said type characters, each of said impression devices being aligned with a respective one of said columns, means for advancing said type past said impression devices, means for guiding a record medium between said type drum and said impression devices, a counter, said counter being adapted to fill upon reaching a count equal to the number of said impression devices, means for selectively actuating said impression devices, means for selectively presenting pulses indicating that certain of said impression devices are not to effect a printing impression, means responsive to operation of each of said last two mentioned means for actuating said counter, and means responsive to lling of said counter for advancing said record medium past said impression devices.

3. Printing mechanism comprising the combination of a type drum having a plurality of columns of type characters spaced therearound, a plurality of impression devices for obtaining a printing impression of selected ones of said type characters, each of said impression devices being aligned with respective ones of said columns, means for advancing said type drum past said impression devices, means for guiding a record medium between said type drum and said impression devices, a counter, means for selectively actuating said impression devices, means for selectively presenting pulses indicating that certain of said impression devices are not to eiect a printing impression, means responsive to operation to each of last two mentioned means for actuating said counter, and means responsive to said counter upon reaching a count equal to the number of said impression devices for advancing said record medium past said impression devices.

References Cited in the le of this patent UNITED STATES PATENTS 2,757,605 Dumey Aug. 7, 1956 2,776,618 Hartley Jan. 8, 1957 2,796,830 Hilton June 25, 1957 2,873,666 Stiefel Feb. 17, 1959 2,919,967 Schwertz Jan. 5, 1960 

1. PRINTING MECHANISM COMPRISING THE COMBINATION OF A TYPE MEMBER HAVING A PLURALITY OF TYPE CHARACTERS THEREON, A PLURALITY OF IMPRESSION DEVICES ASSOCIATED WITH SAID TYPE MEMBER FOR OBTAINING PRINTING IMPRESSIONS OF SELECTED ONES OF SAID TYPE CHARACTERS, MEANS FOR ADVANCING SAID TYPE MEMBER PAST SAID IMPRESSION DEVICES, MEANS FOR GUIDING A RECORD MEDIUM BETWEEN SAID TYPE MEMBER AND SAID IMPRESSION DEVICES, A COUNTER, SAID COUNTER BEING ADAPTED TO FILL UPON REACHING A COUNT EQUAL TO THE NUMBER OF SAID IMPRESSION DEVICES, MEANS FOR SELECTIVELY ACTUATING SAID IMPRESSION DEVICES, MEANS FOR SELECTIVELY PRESENTING PULSES INDICATING THAT CERTAIN OF SAID IMPRESSION DEVICES ARE NOT TO EFFECT A PRINTING IMPRESSION, MEANS RESPONSIVE TO OPERATION OF EACH OF SAID LAST TWO MENTIONED MEANS FOR ACTUATING SAID COUNTER, AND MEANS RESPONSIVE TO FILLING OF SAID COUNTER FOR ADVANCING SAID RECORD MEDIUM PAST SAID IMPRESSION DEVICES. 